I watched this trailer yesterday and was gonna start a thread on it, but the trailer seems to bounce around with too much non-gameplay footage for me to get a real idea of what it's like. You can sort of tell when it clicks into actual GP footage.

Assassin's Creed looks like it's got some similarities. I was thinking like a cross between a hack n slash like Devil May Cry, with some platforming elements like what Uncharted did with the shooter crossed with platforming. It may be more openworlded like AC though.